Staircase Problem

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There is a staircase with N steps, and you can climb one or two steps at a time. Write a function that returns the number of distinct ways to climb the staircase given N. The order of the steps is important.

Write a function solve that have the following parameter(s):
1.) N = an integer

Example
Input:
N= 4
Output:
The function will return,
5

Explanation
There is an input n = 4.
So, There are 5 ways to climb 4 stairs. 1, 1, 1, 1
2, 1, 1
1, 2, 1
1, 1, 2
2, 2

Constraints
• Number of the stairs will be greater than or equal to 1 and less than or equal to 25.